Outdoor navigation and positioning has been widely deployed thanks to the development of various global navigation-satellite-systems (GNSS) as well as various cellular systems. Indoor navigation and positioning differs from the outdoor navigation and positioning since the indoor environment does not enable the reception of signals from satellites or cellular base stations as well as in the outdoor environment. As a result, accurate and real-time indoor navigation and positioning are difficult to achieve.
Thus there are general needs for improved navigation and positioning methods. There are also general needs for improved navigation and positioning methods suitable for indoor environments.